I have four small corys (Peppered - about 1/2" to 1" each) and four small Clown Loaches in a 15 Gallon (once the Clowns start growing I will transfer them to larger quarters). Yesterday after a water change I noticed one of my Loaches had about 3 white spots on him. I began to raise the temperature of the tank and I have covered the tank with a towel and added an airstone.

The other inhabitants of the tank are a 6 tiny white cloud minnows (1/2") one lorry (1 1/2" pl*co - also to be transfered once he grows) and some plants.

How high can I raise the temperature and because of the corys should I add salt? I am not sure that any of the fish will survive in my other tanks as they are all so tiny at the moment. If I cannot use salt should I abandon the high temperature/d